Ignition apparatus



DBC. 12, 1933. Q H. DAWS, JR 1,939,439

IGNITION APPARATUS Original Filed Feb. l1, 1932 Patented Dec. 12, 1933 PATIENT OFFICE IGNITION APPARATUS Charles Hall Davis, Jr., Anderson, Ind., assigner to Delco-Remy Corporation, Anderson, Ind., a corporation of' Delaware Application February 11, 1932, Serial No. 592,290

Renewed July 27, 1932 10 Claims. (C1.` 12B- 148) This invention relates to ignition apparatus for internal combustion engines and more particularly to two cylinder engines. It is an object of thepresent invention to provide an ignition timer distributor unit which operates at less than engine speed and which has a symmetrical arrangement of distributor head inserts or terminal posts.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawing:

Fig. l-is a wiring diagram of an ignition circuit embodying the present invention, and employing a single circuit breaker lever.

Fig. 2 is a modified form of the invention in which two circuit breaker levers operated alternately are provided.

Referring to Fig. 1, 20 designates a battery grounded at 21 connected by a switch 22 with the primary winding 23 of an ignition coil 24 having secondary winding 25. The primary 23 is connected with an'ignition timer terminaly 26 connected by a leaf spring conductor 27 with a circuit breaker lever 28 carrying contact 29 cooperating with a grounded contact 30. `The leaf spring conductor 27 urges the contact 29 toward The cam 32 is driven byl a shafty 33 indicated by dot-and-dash lines which runs at 1/3 engine speed for a two cycle engine and v1/6 engine speed for a four cycle engine.: The shaft 33 drives a distributor rotor block 40 carrying a three-branch rotor 41 whose` branches are marked R1, R2 and R3 respectively. T hese branches are provided Vwith extensions 42 to take care of rotation of the engine in .either direction. The. secondary 25 is connected by wire 43 with a circuit button 44 bearing against the rotor conductor 41. ends of rotor arms R1, .R2 and R3 move past two diametrically opposite posts 45 connected respec- Atively. with the spark gaps 46 of vcylinders #l and #2, respectively.

It will be noted that the cam has six lobes spaced and that the rotor has three branches. Therefore', during 1/3 revolution of 'two crank shaft rotations of a four cycle engine, l

.separate the timer contacts. vsparking impulse will be distributed by rotor R1 The the rubbing block 31 will be engaged by two cam lobes to effect two separations of the pairs of contacts29 and 30 and hence two discharges of the ignition coil 24. At the instant of separation of contacts29 and 30 one of the'branches of rotor 30 conductor 41 will be opposite a post `45 and at the following instant of separation of contacts 29 and 30 another rotor branch will be opposite the other distributor post 45.

The operation of the distributor with respect to the timer can be best understood by the use of indicia applied to twoposts 45. The indicia l-Ll--Rl and theindicia 2-L2R2 not enclosed by parentheses or brackets indicates the operation during the first thirdv revolution of the T0 shaft 33. The lobe L1 engages the block 31 to At this instant a to the left hand post 45 to supply a sparking impulse to the gap 46 in cylinder #1. This fact 7 5 is `represented by the indicia l-Ll-RL which means that cylinder #l is provided with a sparking impulse caused `by Ythev engagement of cam lobe L1 with the rubbing block and this sparking impulse is distributedthrough rotor R1. lAfter -.8.0 a further rotation of 180 of the engine shaft of the two cycle engine or after a further rotation of 360 of crankshaft rotation of a four cycle engine, thelobe L2 will engage the rubbing block andthe rotor R2 will be adjacent the right hand .i 85 end of `the distributor post 45. The indicia 2f- L2-'R2 means that the lobe L2 controls the discharge cfa sparking impulse which is distributed by rotor R2 to the spark plug of cylinder #2. i Y

The indicia(1-L3-R3) and (2-L4-R1) represent what occurs during the next third revolution of the shaft 33 or during the next cycle of operation of the engine. First, the discharge of asparking impulse is controlled by lobe L3 95 and this spark impulse is conducted through rotor branch'` R3 to the left hand post 45 and thence conducted to the sparkplug of cylinder #1. Next the lobe L4 engages the rubbing block to effect the discharge of a sparking impulse 00 fwhich is conducted by rotor R1 to the right hand post 45 andthence conducted to the spark plug of cylinder #2.

T he indicia [1-L5-R2] and [2-L6-R3] represents the manner of effecting the discharge of sparking impulses and the discharge of the same during the next third revolution of the shaft 33 or during the next engine cycle. The indicia V[1-L5-R2] Yrepresents that the cam lobe L5 has yeffected* the discharge of the sparking impulse ilO which rotor branchl R2 distributes to the left hand post connected with the spark plug or cylinder #1. The indicia [2-L6-R3l represents that the cam lobe L6 has eiected the discharge of a sparking impulse which is distributed by rotor branch R3 to the right hand post 45 connected with a spark plug of :cylinder #2.A

Thus the ignition timer cam effects during onev ablefor fanengirie' which is not required lto'op-y "erate'at veryhigh speeds. Fo'r'fa very'hi'gh speed Iengine, the forins'hown Ain Fig. 2 is preferable Vsince :tw'o alternately `operating parallel `circuit breakers in `series 'with 'the 'ignition coil are emiploye'd. Thesecircuit breakers are designated in'their entirety by reference' characters Al :and

``A2. The circuit 'breaker A1 Acomprises contacts and 51 connected respectively `fwith a circuit breaker`lever"52andwith' a grounded bracket 53.

primary `23. The-spring' 54 Y"urges the contact I50 toward the v'tsor'itl'akstS1-and-a rubbing -block V58 "s1 'connected fr'espe'etveiy with '-'cireuit breaker lever 5621 and-'ground'bracket. The lever 62- is Rubbingblocks 58 y'fand '-'B8f'reloc'ated -dia- Y A'inetrically opposite each-other eandthef-'carn-i is a f three lobe, symmetrical cam. "'l'fl'ieeam isso con- *structed and-arranged with 'respect to tlierubbing blocksl- 5 8 Vand" 68` that'each pair f contacts the 'rotn conductor? 41 are-"practically tlliesame ras correspondingly numbered parts of `Fig. "1.

Theiridiia appliedto thedi'strbutr psts 45 v'inllig *2 'have'the same isignicar'iceiinF'Fig. f2

as corresponding indiciahavel With respect to posts If45 Y:in Fig.`1. Therefore nofdet'a'iled ex- A pis-nhen ofi these 'indieiaf is g'ivenrothef'than to statel that the'fliaracterAl' o f the' indicia applied "to the left handr'p'ost 45' off'Fig`.-2"-iridicatesvthe operation ofV circuit breaker `A1"to"ete"ct the' `disis operative to eiTect the discharge 'ofsparking Figi?. In'lig.' 2,':as`fin Fig. l; theretor branches fRl, RZ'and R3 'operate 'in'l recurrent sequence -al- "te'r'nat'ely v"to' distribute "sparking "nosfts 4,5- I. A .Y

I'he ftvvo illustrated exiib'o'diments1ofthe'pres- I impulses to entv inventionl are i'r tvvo'A cylinder engines which iire symmetrically, that is, every 180 of crank shaft rotation forr a two cycle engine and every 360 of crank shaft rotation for a four cycle engine. This invention can be applied to engines having unsymmetrical firing order simply by providing nonsymmetrical timercams and by locating the *distributor posts 45 in a rcorrespondingly nonsymmetrical arrangement.

It is apparent from the foregoing description of the construction and mode of operation of ignition apparatus embodying the present inven tion that the present invention contemplates a distributor head having a center terminal and circularly arranged rposts equal to N, the number of explosion periods occurring during an engine cyele,`saidv circularly arranged posts being connected respectively to engine spark gaps, and a distributor rotor connected with the center terminal and having N+1 branches or arms, said arms moving past said posts and said arms and posts being soarrang'e'dlthat a :group ora 113111- rality 'of `arms less than the total number of farms 'serves alternately during one engineicycle and then Yanother group of arms Vincluding 1an revolution during each engine' cycle. "The induction means which supplies the-center 'contact with a sparking impulse each'itime 'a rotor arm i110 is adjacent a post is contrelle'd by al circuitl inter- `riipter means Vso constructed andy arranged as'to give a sparking impulse for' each Sor' 115 Nz-i-N ofl rotor rotation. (The term [Se: 360V '20 www lis-derived by subtractingfrom spark 'gapjpo'st spacing, ,W :Lao

the rotorarm spacing l n:.130

k360 Nel' l The circuit interrupter means comprises Bf cir-'3135 .'cuit breakers operated upon-alternately"'-by a cam c' rotated 'at rotor speedv and 'having its -l'obes equal '-to. L` which equalsv i y 14o IBS B being "a number such that-.thequotient of is an integer. 1 The followingl'tabulation shows 'the' values 'of-1S; `Bl and L fory engines havingcdif- '150 yferent numbers,

each engine cycle:

While the form off` embodiment of the present invention as herein disclosed constitutes a preferred form, it isfto be understood that other forms might bea'dopted,'all `coming withinthe scope of the claims Ivvhiclf1 follow.

What is claimed. is as follows.

l. Ignition apparatus for a two cylinder engineA comprising, in COmbinatiOn,` means for `producing sparkingim'pulses'one 'at each Yfiring mstant, and means for distributing the impulses comprising two distributor posts connected, respectively, with the'fen'gine spark gaps and a rotor having three branches which operate in recurrent sequence fand 'alternately ,withirespect to the distributor posts, said rotor being driven at such speed that it turns one-third of a revolution during each cycle of engine operation.

2. Ignition apparatus for a twocylinder symlnetrical engine zcomprising, in combination, a shaft driven at such speed that it turns one-third of a revolution during each cycle of engine operation, a six lobe cam driven by the shaft, a circuit breaker controlling an ignition coil and operated upon by the cam, and a distributor comprising two diametrically opposite posts connected, respectively, with the engine spark gaps, and a three branch rotor driven by said shaft for distributing sparking impulses alternately to said posts.

3. Ignition apparatus for a two cylinder symmetrical engine comprising, in combination, a shaft driven at such speed that it turns onethird of a revolution during each cycle of engine operation, a three lobe cam driven by the shaft, two circuit breakers operated alternately by the cam for controlling an ignition coil, and a distributor comprising two diametrically opposite posts connected, respectively, with the engine spark gaps, and a three branch rotor driven by said shaft for distributing sparking impulses alternately to said posts.

4. Ignition apparatus for internal combustion engines having N explosion periods during an engine cyclecomprising, in combination, a distributor head having a center terminal and N circularly arranged posts connected respectively to engine spark gaps and a distributor rotor connected with the center terminal and havingl N+1 branches or arms moving past said posts, said arms and posts being so arranged that a group of a plurality of arms less than the total number of arms serves alternately during one engine cycle, and another group of arms including an arm not operative during the preceding Vcycle serves alternately during the succeeding revolu'tionduring each-engine cycle, and means for providing the center contact with a sparking impulse each time a rotor arm is adjacent a post.

5. Ignition apparatus for internal combustion engines having two explosionY periods during each enginecycle comprising in combinationfa distributor head having a center terminal and two circularly arranged vpostsconnected respectively with spark gaps and a distributing rotor 5 having three branches or armsmoving past said posts, said arms andrposts being so arranged that, vduring one engine cycle," two* arms operate `alternately and that, Vduring the next engine ,cycle', two arms including one not operating `durin'gjthe preceding cycle operate alternately,

andjsoon until the rotor makes one complete l cycle, means forjturning the rotor at the irate off 1/3 revolution during each'engine cycle, and j/"rneansV for providing .therenter contactl with a sparking impulse eachtime a rotor` arm is adjacent a post: f i

6.1 Ignition apparatus for` internal combustion engines having N explosion periods' during an engine cycle comprising, in combination,aI distributor head having a center terminal and N circularly arranged posts connected respectively to engine spark gaps and a distributor rotor connected with the centerv terminal and having N+1 branchesv or arms movingffpast saidposts,

said arms and postsbeingso arranged that the 'arms serve in recurrent sequence and but once during each engine cycle, the sequence being their order of"arrange1nen t, means for .turning revolution during each engine cycle, and means for providing the center contact with a sparking impulse each time a rotor arm is adjacent a post.

7. Ignition apparatus for internal combustion engines having N explosion periods during an engine cycle comprising, in combination, a distributor head having a center terminal and N" revolution during each engine cycle, induction means for generating sparking impulses and circuit interrupter means for causing a sparking impulse to be provided at the center terminal each time a rotor arm is adjacent a post, said interrupter means comprising B circuit breakers operated alternately by a cam having sa BS equal. to Y l Vtol engine sparkgapsanda Ldistributor rotorconinectd WithQthe center terminal Y and having i Nei-l.branches'l or arrnsl,movin'gpast.said posts,

.said1 arms and posts kbeingso v arranged that the g arms function :alternatelyl but each .not more than once in Succession during an engine, cyclel and that, those posts which, are served by Vaj certain Varmdur'ingfa' certainlengine cycleare served by anotherfarm during the nextengine cycle; means tfbreufmnsfth @or f v y .N+ 1; revolution during `each enginecycle, Aand. means f or. providing the *center Contact with a Yspark- :Aling' irnpulse eachftimearotor aimueis adjacent ,..aposte 19. Ignition .apparatus Afoi' an engine. having N A 40 explosionV periods during each engine cycley corn- A,andfB bei-nga number such that the quotient of priing. in combination, a distributor ,cemprisin a head having `a'center 'terminal'and N p os'ts connected respectively with N 'e`r`1`gi`spark gaps and a rotor having N+1 connected arms rotatrevolution, .during each engine cyclaf andcmans for providing a sparking impulse when 'al rotor 85 arm is adjacenty to a post.`

v10.. Ignition apparatus for an engine havingN explosion periodsvdurngj each engine cycle comprising, in combination, adistributor comprising al head khaving a center terminal and N equi- ,90 angularly spaced `posts v connected respectively with N engine spark gaps, andv a rotor having vN -i-l equiangularly spaced connected arms rotating PeSUPQPOSiSLet the rate 0f 1 95 yJH-1 VV revolutions during each, engine cycleand means for generating' afsparking impulse each' so: 36o e Y 1 w+ of,- rotor rotation,V Lsaid means including; B vcircuit breakers operatedalternately by acam rotating atrotor speedand having, L IQbeS equal t0 :,595

Bs B being a number suchthat the quotient of j -o Lai visan integer.

" I cHnRLEs lH ALL pAvIs, Jn. 115 

